The regimen-related toxicities associated with bone marrow transplantation (BMT) can be severe and even life threatening. The overall goal of this randomized controlled pilot study in BMT patients is to determine the effect of relaxation/.stress reduction strategies on: (1) the frequency/severity of toxic side effects of marrow ablative chemotherapy, and (2) the timing of immune reconstitution. A substantial literature indicates that music therapy-based interventions are effective in inducing relaxation and also affect immune function by modulating circulating and salivary levels of such agents as cortisol, immunoglobulin A, interleukin-1, natural killer cells, and a variety of other immune system-related substances. Over the past two years, we have provided music therapy-based stress reduction/relaxation interventions to a convenience sample of patients undergoing BMT. Preliminary findings from this pilot feasibility study demonstrate that patients report significantly decreased pain (p< .004) and sense of nausea (p < .001) following an intervention. Average time-to-engraftment was 13.5 (+/- 2.85) days as compared to 15.5 (+/- 4.40) days (p < .O1) for a group of historical controls matched on diagnosis, type of transplant, conditioning regimen, date of transplant, age, and gender. Although highly promising, our data are limited by lack of randomization, an appropriate control condition, measurement of psychologic factors known to influence outcome in BMT, and systematic monitoring of early phase markers of immune reconstitution that could help explain the phenomena we have observed. This proposal corrects these shortcomings and especially highlights the potential mediational effect of cytokine release on regimen-related toxicities and the timing of immune reconstitution.